Mainframe Developer
Confirmed on the employer's own hiring board on Nov 13, 2026. First seen by Alion on Nov 13, 2026.
About The Role
We are adding new composite reservoir accounts to our existing mainframe accounting platform: a pooled account structure in which balances from multiple subsidiary accounts are concentrated into, and drawn back from, a single reservoir account under defined sweep and allocation rules.
This is additional function inside a legacy system. You will be reading a large body of COBOL that has been in production for an extended period, much of it lightly documented, and extending it so that the new account type posts, settles, accrues, reports, and reconciles exactly as the existing types do. Correctness and traceability of every cent matter more than speed of delivery.
What You Will Do
- Analyze the current account master, posting, and balance-maintenance programs to establish where composite reservoir accounts must be recognized, and document what you find.
- Design and code the new account type end to end: master file and table structures, account opening and closing, participant linkage, sweep and reverse-sweep logic, allocation and interest apportionment, and closing balance derivation.
- Modify batch COBOL programs and JCL and extend the nightly and month-end cycles to include the new processing without lengthening the batch window beyond agreed limits.
- Add new CRAs to the audit trail, exception reporting, and reconciliation controls the new function requires, working with accounting stakeholders on what must be evidenced.
- Produce test data, unit and regression test packs, and parallel-run comparisons against current production output; investigate every difference until it is explained.
- Support implementation, conversion of any in-scope existing accounts, and early-life production runs, including on-call cover during the first cycles.
- Leave behind program documentation, data-flow notes, and runbook updates that the support team can work from.
Required Skills
- 5+ years of Enterprise COBOL development experience in a z/OS environment
- 3+ years of composite reservoir accounts.
- 5+ Years of Experience with NaturalOne
- 3+ years of JCL development and production support experience
- 3+ years of experience with financial/accounting systems development or support including double-entry posting, balance/accrual maintenance, value dating, reconciliation, and month-end closeouts in a regulated environment
- 3+ years of experience working with Adabas and VSAM
- 3+ years of experience with tracing undocumented logic through copybooks, call chains, and job streams
These are the skills we expect to see evidence of in the first conversation.
- COBOL - substantial production experience in Enterprise COBOL on z/OS, both batch and online; comfortable extending large existing programs and reading code you did not write.
- NaturalOne - the Eclipse-based Software AG development environment; developing, debugging, and deploying Natural applications from it, including local development and remote z/OS projects.
- Natural and Adabas - Natural programs, subprograms, and maps; DDMs, descriptors and superdescriptors, and Adabas file design and performance behavior.
- z/OS and JCL - writing and debugging JCL, procs, GDGs, utilities, SORT, and restart/rerun handling; fluent in TSO/ISPF.
- Mainframe data stores - VSAM file design and access, and Adabas for z/OS.
- Financial accounting logic - double-entry posting, balance and accrual maintenance, value dating, reconciliation, and month-end close in a regulated environment.
- Analysis of legacy systems - tracing undocumented logic through copybooks, call chains, and job streams, and stating clearly what a change will and will not affect.
Preferred Skills
- Experience with cash management, account pooling, sweeps, or treasury applications
- Experience with CA-7 scheduling and batch operations
- Experience with REXX, Python, or Java
Not required to apply. Each of these will shorten your ramp-up, and we will support you in learning the ones you do not have.
- Mixed-estate integration - calling between COBOL and Natural, and exposing mainframe function through z/OS Connect, IBM MQ, or REST services.
- Scheduling and operations - CA-7 batch window analysis and performance tuning.
- Scripting and adjacent languages - REXX or CLIST for tooling, plus Java or Python for data comparison and migration work.
- Cash management domain - notional and physical pooling, cash concentration, sweeps, and intercompany allocation.
Additional Skills
- Track record of taking a specification from analysis through production implementation with limited supervision.
- Clear written communication: you can explain a change to an auditor, a business analyst, and another developer, and adjust the explanation for each.
- Degree in computer science or a related field, or equivalent practical experience.
How We Work
- Production changes follow formal change control with peer review and a signed-off implementation plan.
We are adding new composite reservoir accounts to our existing mainframe accounting
platform: a pooled account structure in which balances from multiple subsidiary accounts
are concentrated into, and drawn back from, a single reservoir account under defined
sweep and allocation rules.
This is additional function inside a legacy system. You will be reading a large body of
COBOL that has been in production for an extended period, much of it lightly documented,
and extending it so that the new account type posts, settles, accrues, reports, and
reconciles exactly as the existing types do. Correctness and traceability of every cent
matter more than speed of delivery.
What You Will Do
- Analyze the current account master, posting, and balance-maintenance programs
to establish where composite reservoir accounts must be recognized, and
document what you find.
- Design and code the new account type end to end: master file and table structures,
account opening and closing, participant linkage, sweep and reverse-sweep logic,
allocation and interest apportionment, and closing balance derivation.
- Modify batch COBOL programs and JCL and extend the nightly and month-end
cycles to include the new processing without lengthening the batch window beyond
agreed limits.
- Add new CRAs to the audit trail, exception reporting, and reconciliation controls the
new function requires, working with accounting stakeholders on what must be
evidenced.
- Produce test data, unit and regression test packs, and parallel-run comparisons
against current production output; investigate every difference until it is explained.
- Support implementation, conversion of any in-scope existing accounts, and early-
life production runs, including on-call cover during the first cycles.
- Leave behind program documentation, data-flow notes, and runbook updates that
the support team can work from.
Required Skills
- 5+ years of Enterprise COBOL development experience in a z/OS environment
- 5+ Years of Experience with NaturalOne
- 3+ years of JCL development and production support experience
- 3+ years of experience with financial/accounting systems development or
support including double-entry posting, balance/accrual maintenance, value
dating, reconciliation, and month-end closeouts in a regulated environment
- 3+ years of experience working with Adabas and VSAM
- 3+ years of experience with tracing undocumented logic through copybooks,
call chains, and job streams
These are the skills we expect to see evidence of in the first conversation.
- COBOL - substantial production experience in Enterprise COBOL on z/OS, both
batch and online; comfortable extending large existing programs and reading code
you did not write.
- NaturalOne - the Eclipse-based Software AG development environment;
developing, debugging, and deploying Natural applications from it, including local
development and remote z/OS projects.
- Natural and Adabas - Natural programs, subprograms, and maps; DDMs,
descriptors and superdescriptors, and Adabas file design and performance
behavior.
- z/OS and JCL - writing and debugging JCL, procs, GDGs, utilities, SORT, and
restart/rerun handling; fluent in TSO/ISPF.
- Mainframe data stores - VSAM file design and access, and Adabas for z/OS.
- Financial accounting logic - double-entry posting, balance and accrual
maintenance, value dating, reconciliation, and month-end close in a regulated
environment.
- Analysis of legacy systems - tracing undocumented logic through copybooks, call
chains, and job streams, and stating clearly what a change will and will not affect.
Preferred Skills
- Experience with cash management, account pooling, sweeps, or treasury
applications
- Experience with CA-7 scheduling and batch operations
- Experience with REXX, Python, or Java
Not required to apply. Each of these will shorten your ramp-up, and we will support
you in learning the ones you do not have.
- Mixed-estate integration - calling between COBOL and Natural, and exposing
mainframe function through z/OS Connect, IBM MQ, or REST services.
- Scheduling and operations - CA-7 batch window analysis and performance
tuning.
- Scripting and adjacent languages - REXX or CLIST for tooling, plus Java or Python
for data comparison and migration work.
- Cash management domain - notional and physical pooling, cash concentration,
sweeps, and intercompany allocation.
Additional Skills
- Track record of taking a specification from analysis through production
implementation with limited supervision.
- Clear written communication: you can explain a change to an auditor, a business
analyst, and another developer, and adjust the explanation for each.
- Degree in computer science or a related field, or equivalent practical experience.
How We Work
- Production changes follow formal change control with peer review and a signed-off
implementation plan.
Requirements
Required Skills
Skill Type
Skill Name
5+ years of Enterprise COBOL development experience in a z/OS environment
5+ Years of Experience with NaturalOne
5+ years of JCL development and production support experience
3+ years of experience with financial/accounting systems development or support including double-entry posting, balance/accrual maintenance, value dating, reconciliation, and month-end closeouts in a regulated environment
3+ years of experience working with Adabas and VSAM
3+ years of experience with tracing undocumented logic through copybooks, call chains, and job streams
3+ years of composite reservoir accounts
Preferred Skills
Skill Type
Skill Name
Experience with cash management, account pooling, sweeps, or treasury applications
Experience with CA-7 scheduling and batch operations
Experience with REXX, Python, or Java